The present invention relates to tire breakdown warning devices which detect a breakdown of a pneumatic tire to impart a warning and pneumatic tires having a temperature sensor thereof, and more particularly, to a tire breakdown warning device and a pneumatic tire in which detection accuracy of tire breakdown can be improved.
If traveling of a vehicle is kept without awareness of occurrence of tire breakdown during traveling, there is a risk that a serious traffic accident will be developed by burst of the tire. In particular, when traveling at high speed on an expressway or the like, a disastrous traffic accident will happen. Therefore, when tire breakdown occurs, it is very important to find it immediately.
Disclosed in Unexamined Japanese Patent Publication No. 3-262716 and Unexamined Japanese Utility Model Publication No. 63-189703 are conventional tire breakdown detection devices which use a temperature sensor, in which the temperature sensor detects temperature of a surface or cavity of a tire and tire breakdown is determined by change of the temperatures. Occurrence of breakdown of a pneumatic tire significantly increases heat generated at a breakdown spot, and it is, therefore, very effective to find tire breakdown using the temperature sensor.
However, breakdown of a pneumatic tire generally occurs at an end of a tire constituent component such as a belt ply or carcass ply embedded in the tire, or inside of the tire in a shoulder area of a tread or the like having a thick rubber layer portion when an excessive load is applied thereto. The conventional devices described above do not directly detect temperature inside the tire where breakdown occurs. Therefore, there is a problem of detection accuracy such that there is a delay in the detection of tire breakdown, and there is still room for improvement.